// let MY_NAME=Symbol()
// let a={}
// a.username='zs'
// a[MY_NAME]='ls'
// console.log(a);
let MY_NAME=Symbol('s1')
let Age=Symbol()
let Addr=Symbol()
let a={
    [Age]:18
}
a.username='zs'
a[MY_NAME]='ls'
let b={}
Object.defineProperty(b,Addr,{value:"湖南长沙"})
console.log(a);
Object.defineProperty(b,'add',{value:123})
console.log(b);